Assessment of the optic nerve head, peripapillary, and macular microcirculation in the newly diagnosed patients with primary open-angle glaucoma treated with topical tafluprost and tafluprost/timolol fixed combination

RELEVANCE: The ability of antiglaucoma drugs to improve ocular hemoperfusion is an important aspect of their action. Tafluprost is the first preservative-free prostaglandin analog. The efficacy and safety of tafluprost, as well as tafluprost/timolol fixed combination (FC), were demonstrated in randomized multicenter trials. However, there is no literature on the effect of tafluprost and its FC on the peripapillary and macular blood flow. PURPOSE: To determine the changes of microcirculation in the optic nerve head (ONH), peripapillary retina, and macula in patients with newly diagnosed primary open-angle glaucoma (POAG) under the topical tafluprost and tafluprost/timolol FC treatment. MATERIALS AND METHODS: Optical coherence tomography angiography (OCT-A) was performed in dynamics with an interval of a week in 36 patients (36 eyes) with a newly diagnosed initial stage of POAG: 12 eyes with tafluprost, 12 – tafluprost/timolol FC, and 12 – no topical treatment (the control group). The change in intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) of the eye, and vessel density (VD) inside the ONH (inside disc), as well as in the peripapillary retina and macula, was evaluated by comparing paired repeated observations using the median growth analysis. RESULTS: In the tafluprost group, there were a decrease in IOP by 19.4% and an increase in MOPP by 8.7% from the reference level. In the tafluprost/timolol group, these figures were 43% and 30.1%, respectively. OCT-A values did not change reliably, except for VD inside disc: the median growth of the tafluprost group was 2.28 (P = 0.02) and of the tafluprost/timolol group was 1.82 (P = 0.03). These changes were obtained in 11 of 12 patients in each group under treatment. In control group, all indicators remained unchanged. CONCLUSIONS: A significant increase of MOPP and a decrease of VD in the ONH in patients with initial glaucoma occurred within a week under the topical tafluprost or its FC. This can be explained by the restoration of autoregulation of the ocular blood flow in conditions of pronounced hypotensive effect of the drugs.